What size restrictor for the DBB turbo


currently have a silver color restrictor for the DBB turbo. Problem is blue smoke from the tail pipe, does get a little better when the motor warms up. never had this problem with a journal bearing turbo.

would it be safe to go with a smaller restrictor? pressure at idle did go up to 30 when the ball bearing turbo was switched (when hot). Would it be possible to move the restrictor from the top of the turbo to anoter location?

do I /should i lower the oil pressure from the pump?